Support naming knockout rounds

[PeterJCLaw]

Mostly for internal reference; currently this is done with comments, however for complex knockout structures it may be useful to be able to convey names out to display screens etc.

[PeterJCLaw]

This may not make sense to have in the automatic knockout scheduler and is likely hard to add in a compatible manner to the static scheduler, however feels like a good candidate for adding to the planned structured knockout scheduler.